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Use this form to add a new glossary term, or update a current term.

  • A-Frame

    1. A telescoping structural member used to attach the bottom of the leads to the crane base and used to position or batter leads in or out, left or right. Can be mechanically, hydraulically or pneumatically operated; it is used with either fixed leads or semifixed leads. Also called Bottom Brace, A-Frame, Spotter, Spreader Bar, […]

  • A/E or E/A

    Abbreviation for Architect/Engineer or vice versa.


    American Association of State Highway and Transportation Officials.

  • acceptance test

  • ACI

    American Concrete Institute.

  • ACIP, ACIP Pile

    See Augered, Cast-in-Place Pile

  • active earth pressure

  • Adaptor

    Structural steel fabrication or iron casting placed in a pile helmet to adjust to a different type or size of pile. Also called filler or insert.

  • additive

  • Adfreezing

    The adhesion of soil to a foundation unit resulting from the freezing of soil water. Also referred to as “frost grip.”

  • adhesion

  • Adjacent Piles

    The nearest piles to a given pile or location

  • admixture, addition


    The International Association of Foundation Drilling – Formerly the Association of Drilled Shaft Contractors

  • adsorbed water

    Water bound to soil particles because of the attraction between electrical charges existing on soil particle surface and (dipole) water molecules.

  • Advance Splicer

    Trade name for a tapered steel unit for connecting pipe piles by driven friction.

  • Aeolian soil

    Soil mainly composed of silt-sized particles of wind blown deposits. See also Loess, which is aeolian soil.

  • AFEO

    ASEAN Federation of Engineering Organisations. Engineering Organization consisted of ten national professional engineering organisation from ten ASEAN (Association of Southeast Asian Nations) countries

  • Aft Batter

    Colloquial term for driving a pile at an angle from the vertical where the bottom of the pile is inclined toward the crane. Same as Negative Batter. See also Inclined Pile

  • AGC

    American General Contractors Association

  • aggregate

  • air

  • air entrainment

  • air hose

  • Air Port(s)

    The ports on a diesel hammer which serve as both air intake and air exhaust ports.

  • Air/Steam Hammer

    Impact pile driver powered by compressed air or steam; action of machine may be single, double, differential or compound.

  • Airlift

    Device for lifting slurry, suspended solids and drill cuttings from the bottom of a bentonite or polymer slurry-filled excavation for a trench, coffer dam cell or drilled shaft. Usually, compressed air is introduced into the slurry at the bottom of the excavation via a small pipe inside a larger pipe. The upward airflow inside the […]

  • Airlock

    Device use to control internal pressure of Pneumatic caissons.

  • Airport

    The ports on a diesel hammer which serve as air intake and exhaust ports.

  • allowable bearing value

  • Allowable Load

    The maximum load permitted, considering structural strength, bearing capacity, horizontal movement, code requirements, or measured settlement in a load test.

  • alluvium

    A sedimentary soil deposit that has been transported by water.

  • anchor

    Mechanical device used to transfer load (tension or compression) from a superstructure to supporting soil/rock

  • anchor head

  • Anchor Pile

    1. Piles driven behind retaining walls, and beyond the area where soil may slip, to which a retaining wall’s tie-back rods or cables are attached . See also Deadman. 2. Piles constructed near test pile to anchor jacking beam (See also Reaction Pile).

  • anchor wall

  • anchorage, anchoring, anchor plate

  • anchored bulkhead

  • Angle Iron Guides

    A part fitted to the sides of a pile hammer which engage the rails of a set of leads to hold the hammer in the leads. Also called Side Guides, Angle Iron Guides, Grooves, Gibs, Jaws, Ways.

  • Angle of Internal Friction

    Value used in soil analysis approximately equal to the angle formed by a naturally occurring pile of cohesionless soil.

  • angle of repose

  • anode

  • Anomaly

    An irregular response or unexpected signals detected by non-destructive testing.

  • Anvil

    1. The part of a pile hammer seated directly under the ram which transmits the blow of the ram to the pile or to the drive cap (also called Impact Block). 2. Steel plate on top of cushion material in drive cap which impact block strikes. Also called Anvil Block, Penny, Striker Plate or Top […]

  • API

    American Petroleum Institute.

  • apparent tendon free length

  • applied stress

  • apron

    A telescoping structural member used to attach the bottom of the leads to the crane base and used to position or incline leads in or out, left or right. Can be mechanically, hydraulically or pneumatically operated; it is used with either fixed leads or semifixed leads. Also called Bottom Brace, A-Frame, Spotter, Spreader Bar, Spider, […]

  • aquiclude

  • Aquifer

    A soil layer that carrries water.

  • arching

  • Artesian Head

    The amount by which water pressure in an aquifer that causes water to rise above the normal groundwater table or the ground surface.

  • artesian pressure

  • Artesian Water

    Subsurface water with sufficient pressure (head) to raise the water in a well or pipe above the normal groundwater table or ground surface.

  • ASCE

    American Society of Civil Engineers.

  • ASFE

    American Society of Foundation Engineers.

  • ASTM

    American Society for Testing and Materials.

  • at rest pressure

  • Atomization, Impact

    A type of fuel atomization used in a diesel hammer in which the raw fuel injected and trapped between the ram and the anvil is atomized by impact of the ram on the impact block. The hammer normally will have a time delay between impact and combustion.

  • Atomization, Injection

    A type of diesel fuel atomization used in a diesel hammer in which the fuel is atomized by an injector. Combustion will normally occur prior to impact.

  • Atterberg limits

    The liquid limit, plastic limit and plasticity index for soil. The water content where the soil behavior changes from the semi-liquid to the plastic state is the liquid limit and from the plastic to the semi-solid state is the plastic limit. Plasticity index is the numerical difference between liquid limit and plastic limit and is […]

  • auger

    1. A helically shaped corkscrew-like tool with a power driving head on top and a cutting head on the bottom, designed to bore holes in the earth by drilling, either with or without the supplementary use of water. 2. A hand operated soil sampler.

  • auger boring

  • auger flights

    Sections of a continous flight auger “quick-coupled” together to form a continous auger. See Continous Flight Auger

  • Auger Refusal

    The point at which auger advance ceases, or slows to a predetermined rate due to the strength of the soil or rock being drilled.

  • Augercast, Augercast Pile

    A proprietary name for an augered, cast-in-place (ACIP) pile

  • Augered Cast-in-Place (ACIP) Pile

    ACIP piles are constructed by rotating a continuous-flight, hollow-stem auger into the ground to the specified bearing depth, or until the refusal criteria are reached. Fluid grout is then pumped, under pressure, through the hollow stem and out of a port on the bit, as the auger is withdrawn in such a way as to […]

  • augered pile

  • Automated Monitoring Equipment

    Electronic device to automatically record augered, cast-in-place pile installation data during drilling and grouting.

  • AWPA

    American Wood Preservers’ Association – Primary standards writing body for pressure treatment of wood, including pressure-treated timber piling. American Wood Preservers Institute provides technical assistance and use specifications. American Wood Preservers Bureau is concerned with quality control of pressure treated wood.

  • AWS

    American Welding Society.

  • Back-Up-Ring

    Steel ring placed on inside of pipe to back-up a butt or bevel weld. Also called Chill Ring.

  • backfill

    Soil material placed into a space that has been excavated, such as against structures and in pipe trenches, and in foundations.

  • backhoe

  • bailer

  • banding

    Wrapping timber piles with high-tensile steel bands to prevent splitting while driving. Also called Strapping.

  • barrette

    Cast-in-place concrete foundation element that may be reinforced, which is constructed in various plan configurations (I, H, L, X shapes) and intended to primarily carry vertical loads. Also called load-bearing element.

  • Basal Heave

    See Bottom Heave

  • base failure

  • basement

  • battered pile

    Colloquial term for a pile installed on an incline. See Inclined Pile

  • beam

  • bearing capacity

    The maximum load a pile can sustain by soil/rock resistance at the bottom of the pile. For shallow foundations, it is the capacity of the soil/rock to carry load without excessive deformation.

  • bearing pile

    A supporting pile for a structure that can be of wood, concrete or steel in any number of shapes and whose bearing is reached by toe or end bearing, friction, or friction and compaction, or a combination. See End Bearing Pile

  • bearing pressure

  • Bearing Pressure, Allowable

    The maximum pressure that may be safely applied to a soil or rock by the foundation unit considered in design under expected loading and subsurface conditions.

  • Bearing Pressure, Design

    The pressure applied to a soil or rock by a foundation unit; it is equal to or smaller than the allowable bearing pressure.

  • Bearing Surface

    The contact surface between a foundation unit and the soil or rock upon which it bears.

  • Bearing Wall

    A wall that supports vertical load, as floors or roof.

  • bedrock

    Solid rock as distinguished from boulders or layers.

  • Bell

    Enlargement of the lower end of an augered or drilled pile, shaft or caisson to increase its bearing area. Also called Under-ream.

  • belled anchor

    An area enlarged around a soil anchor for added grout and resistance.

  • belled caisson

    A large-diameter drilled shaft with an enlarged base. See also Caisson

  • bending

  • bending moment

  • bentonite

    Sodium montmorillonite, a mineral clay. A highly compressible colloidal clay which, when introduced into certain soils, reduces their permeability. 1. Introduced in pellet form and tamped into place to restrict water seepage. 2. Suspended in water to form a slurry, Bentonite Slurry, helps to prevent earth from falling into an augered hole or excavated trench. […]

  • berm

    Sloping surface of soil providing lateral support to wall.

  • Bevel Weld

    Butt weld where pieces to be joined have one or both edges beveled, because material is too thick for electrode to penetrate for a required weld.

  • blast, to

  • bleed

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